Just had all three replaced in my auto. She is sooo much happier now. Sits right on 80 degrees 24/7. Used to be anywhere from 90 to 110. Has a lot more get up and go now that its running cooler too. I'm expecting a little gain in gas mileage as well. Just thought I would share my joy a bit.:beerchugr:
New Radiator + Fan Clutch + Thermostat = Happyness
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Nice way to start the warm weather season. Now you can try to wean yourself off of watching the temp guage so often ;-)
About a dozen 1988, 1989, 1990, and 1991 sedans, wagons, 4Matics and 1 coupe
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Define "huge difference." From an engineering standpoint, the higher the operating temperature (to a point, of course) the greater the efficiency of an engine. Seeing a lower reading on the temp gauge doesn't necessarily mean better.
With that 79 deg C thermostat, You are going to see lower gas mileage and rich burning in your engine. Your engine is designed to run at 87 deg C. If your car overheats with the correct thermostat, your coling system has problem.
BTW, 90 - 100 deg C is completely normal, especially in hot whether and stop and go traffic. You might have a partially failing thermostat to start with.
Cooler does not mean better.
BTW, 90 - 100 deg C is completely normal, especially in hot whether and stop and go traffic. You might have a partially failing thermostat to start with.
Cooler does not mean better.
If that really is the case I'm okay with that. Seeing the needle rest right on 80 degrees every time i glance at it simply makes me happy. I didnt do the thermo change to treat the overheating problem, but just for overall benefit. This is something I have done on several of my cars (this is also a common practice among f-body owners). I have been told by "qualified technicians" that the reason mercedes and many other auto makers engines run as hot as they do is for emissions purposes. Dont get me wrong. There are a lot of cars that you absolutely should not do this on and they can respond very negatively, but the m103 motor seems to like it. It makes me happy and I think it could make other w124 owners out there happy as well. Dont knock it till you try it.
And in response to augapfel, I am pretty much totally positive that a higher operating temperature does not mean a more efficient engine, a cleaner burning engine, yes, but more efficient, no. Otherwise there would be no intercoolers on turbocharged cars and the guys at the drag strip wouldnt be ceramic coating their headers.
And in response to augapfel, I am pretty much totally positive that a higher operating temperature does not mean a more efficient engine, a cleaner burning engine, yes, but more efficient, no. Otherwise there would be no intercoolers on turbocharged cars and the guys at the drag strip wouldnt be ceramic coating their headers.
I am not knocking it. I am just trying to give you good advice. It is only a car (yours) and you can do whatever you want.
However, after you own several Mercedes for a while and come back to this "mod", you will feel "why did I do that then?"
I will tell you longtime and experienced MB owners will change their 87 deg C thermostat the first sign when the coolant temp is only at 80 deg or slightly below after a long enough drive. This is the classic sign of a fatigued MB thermostat. The T-stat is partially stuck open so it cannot reach the designed and ideal temperature of 87 deg C. Usually a slightly stuck open T-stat cannot open fully either and that could cause overheating of the engine. These slightly bad T-stats will also have a wider swing range of the coolant temperature.
These T-stats typically last about 60k miles and some owners change theirs on every other coolant flush (5 - 6 years). A new T-stat will always make the coolant temperature reading a needle width above 80 deg C and stick to that position with minimal swings unless it is really hot outside and AC is on and the traffic is stop-and-go.
If a car does not reach the designed operating temperature, the engine management will run the engine in open loop constantly by injecting more fuel. This is certainly not good for the engine and your pocket book. The consequences are more wear, oil gets dark faster, spark plug fouling, etc.
Speaking by an owner who has owned three (3) M103/M104 engine powered MB's for more than 10 years.
However, after you own several Mercedes for a while and come back to this "mod", you will feel "why did I do that then?"
I will tell you longtime and experienced MB owners will change their 87 deg C thermostat the first sign when the coolant temp is only at 80 deg or slightly below after a long enough drive. This is the classic sign of a fatigued MB thermostat. The T-stat is partially stuck open so it cannot reach the designed and ideal temperature of 87 deg C. Usually a slightly stuck open T-stat cannot open fully either and that could cause overheating of the engine. These slightly bad T-stats will also have a wider swing range of the coolant temperature.
These T-stats typically last about 60k miles and some owners change theirs on every other coolant flush (5 - 6 years). A new T-stat will always make the coolant temperature reading a needle width above 80 deg C and stick to that position with minimal swings unless it is really hot outside and AC is on and the traffic is stop-and-go.
If a car does not reach the designed operating temperature, the engine management will run the engine in open loop constantly by injecting more fuel. This is certainly not good for the engine and your pocket book. The consequences are more wear, oil gets dark faster, spark plug fouling, etc.
Speaking by an owner who has owned three (3) M103/M104 engine powered MB's for more than 10 years.
I hope you wouldn't mind if I make a follow-up question/inquiry.
I myself am a bit anxious as I recently acquired a pre-owned 124034 with an M119 powerplant. I've noticed that my engine once warmed up is constant at 100c with the auxilliary fan kicking to life when it goes above 100c.
Is 100c perfectly normal for an M119?
I am planning to fiddle with the car and intending to replace the thermostat to one which can keep my engine temp constant at 80c.
Appreciate those knowledgeable to share some inputs as I am barely a week into owning this beautiful car.
Thank you.
I myself am a bit anxious as I recently acquired a pre-owned 124034 with an M119 powerplant. I've noticed that my engine once warmed up is constant at 100c with the auxilliary fan kicking to life when it goes above 100c.
Is 100c perfectly normal for an M119?
I am planning to fiddle with the car and intending to replace the thermostat to one which can keep my engine temp constant at 80c.
Appreciate those knowledgeable to share some inputs as I am barely a week into owning this beautiful car.
Thank you.
1976 BMW 2002. 1991 250TD. 1995 E320. 2018 Honda Africa Twin
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westonian said:
you realise that you are talking about two completely different things; intake air temperature and coolant temepature. im not going to explain how they are different.
but just to give you an analogy. if what you say is true, then carburetted cars ran better when they were cold than when they were hot. true??? NOT!!!!!!!!!
the reason why you needed them to "warm up" is cause they didnt run as well or efficiently when cold.
im a leave well enough alone type of guy, unless you have constant high temperatures. in this case, high is any number that is above 115. the operating temps for these cars depends on many situations and circumstances, but 90 is perfectly fine, as is 110. this is one of the reasons why they use a pressurised cooling system; the pressure increases the boiling point of water safely.
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